ENGLISH ELECTRIC TRAVELLING WAVE TUBE N1001 VALVE, 1963

Micro Wave amplifying device that works by slowing the electrons through a coil of wire so that the beam of electrons running through it are caused to bunch. The signal through the wire is slower because it has further to travel, hence the name,Travelling Wave Tube.
The bunching of electrons inside the coil is caused by interaction with the beam passing through it, at the first area of bunched electrons some energy is imparted back to the coil, as the process continues the bunch grows so that the next area of bunching becomes larger. this process continues all the the way to the end of the tube.
Travelling Wave Tubes are used in Micro Wave link amplifiers and satellite systems.

Your comments:

• Long time ago I was at Birmingham Radio, and changed one or two TWTs. The worst bit was pushing the collector between the magnets as they attracted the metal end. I remember adjusting the focus with an allen key. On the 1016 system the very high voltage was housed at the bottom of the rack and was very heavy.
  .......... Norman Blackburn, Birmingham, 19th of July 2017
  
  

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